Steering shaft zerk fitting location

[gsdog2]

I have an 87' and was wondering if one were to drill and tap for a zerk fitting in the steering shaft, were would be the best place to put it. More towards the steering box or the firewall? The female half is splined, so on top of one of the splines or in the recess; and is there even enough metal there to tap a hole? Thanks.

 

[FJ40Jim]

There is a rubber plug in the top of the steering box/shaft heat shield, to access the zerk on early steering shafts. Seems like that would be a good place to install one on a later un-zerked shaft.